Peripubertal serum dioxin concentrations and subsequent sperm methylome profiles of young Russian adults.

Background: The association of exposure to endocrine disrupting chemicals in the peripubertal period with subsequent sperm DNA methylation is unknown. Objective: We examined the association of peripubertal serum 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) concentrations with whole-genome bisulfite sequencing (WGBS) of sperm collected in young adulthood. Methods: The Russian Children's Study is a prospective cohort of 516 boys who were enrolled at 8-9 years of age and provided semen samples at 18-19 years of age. WGBS of sperm was conducted to identify differentially methylated regions (DMR) between highest (n=4) and lowest (n=4) peripubertal TCDD groups. Results: We found 52 DMRs that distinguished lowest and highest peripubertal serum TCDD concentrations. One of the top scoring networks, "Cellular Assembly and Organization, Cellular Function and Maintenance, Carbohydrate Metabolism", identified estrogen receptor alpha as its central regulator. Conclusion: Findings from our limited sample size suggest that peripubertal environmental exposures are associated with sperm DNA methylation in young adults. (C) 2018 Elsevier Inc. All rights reserved.